Osteotome



Nov. 17, 1942.

M. T. SEAGRAVE OSTEOTOME Filed pct. 12, 1940 2 Sheets-Sheet 1 mai- INVENTOR. Mes/ML Z JEAGPA w:

2 Sheets-Sheet 2 INVENTOR. flfiqesmu T554 6AM 1/5 A TTORNE Y M. T. SEAG RAVE OSTEOTOME Filed 001;. 12, 1940 Nov. 17, 1942.

Patented Nov. 17, 1942 EN a e OSTEOTOME Marshal T. Seagrave, Palo Alto, Calif., assignor of one-half to Calif.

Clarence E. Butler, Oakland,

Application October 12, 1940, Serial No. 360,907

1' Claim. (01. 32-61) V The invention, in general, relates to dental instruments and more particularly relates to means for facilitating the extraction of teeth.

One of the most common tasks confronting those in the practice of dentistry is that of extraction, and such work is now often referred by those skilled in the art to specialists, or exodontists. As a general rule, the extraction of any given tooth, either from the alveolar processes of the mandible or of the maxilla, does not present a particularly difficult problem to a proficient exodontist, especially where he is aided by an X-ray picture showing the location and direction taken by the roots of the tooth to be extracted. However, notwithstanding X-ray photography, it frequently occurs that extraction is impossible without a division of the alveolar processes adjacent to the tooth being worked upon. This is due to the fact that the alveolar process on the labial side of the tooth has a relatively high elasticity, the tension of which cannot be snapped or overcome by the normal force or pull, that can be exerted with the use of forceps, without recourse to violent means and ensuing trauma. In making or effecting a fracture (division) of the alveolar process adjacent to the tooth to be extracted, those skilled in the art have heretofore utilized chisels, or other like instruments independent of the conventional dental forceps, which use often results in a splintering or shattering of the bony plate,

and consequently tedious labor on the part of the 'exodontist in removing portions of the splintered bone, as well as shoclrand discomfort to the patient.

A primary object of 'my invention is to provide a dental instrument affording the dual function of forceps and bone-dividing element so that extraction of teeth can be accomplished with ease and a minimum of time.

Another object of the present invention is to provide anosteotome of the aforementioned nature which is additionally characterized by its ease of manipulation and dependability of operation.

A still further object of the invention is to provide a dental instrument of the aforementioned character which affords a positive grip upon a tooth to be extracted and simultaneously positions the dividing element for actuation.

Another object of my present invention is to provide an instrument of the aforementioned character which affords a localized (division) of the labial alveolar process rather than a splintering or shattering fracture therefracture another adjacent the pininthe usual manner so of adjacent a tooth to be extracted and thus enables extraction of a given tooth with a ,minimum'of pain and discomfort to a patient as well as speedy extraction. I

Another object of the present invention is to provide a relatively heavy duty 'dental instrumentexemplified in a light duty structure.

A still further object of the present, improvement is to provide anosteotome of the indicated nature which is relatively inexpensive and simple to manufacture.

Other objects of the invention, together with some of the advantageous features thereof, will appear from the following description of aweferred embodiment of the invention, as well as certain modifications thereof, which are illustrated in the accompanying drawings. While I have depicted certain embodiments of the invention'in the drawings, it is to be understood that I am not to be limited to the precise embodiments shown, nor to the precise arrangement of the combined elements, as my inventin', as defined in the appended claim, can be embodied in a plurality'and variety of forms.

Referring to the drawings:

Figure 1 is a perspective view of a preferred embodiment of the invention.

Figure 2 is a side elevational view of the preferred embodiment of my invention, this View showing the instrument as applied to a tooth.

Figure 3 is a perspective View of a modified embodiment of the invention.

Figure'4 is aside elevational View of the modifi'cation illustrated in Figure 3, this view show- 15 ing the instrument. as applied to a tooth.

' said dividing element.

'As illustrated in Figures 1 and 2 of the drawings, that portion of the osteoto-me of my invention which affords a gripping action upon a tooth to be extracted comprises a pair of forceps of somewhat the conventional" type which includes a pair of handles H and [2 each having a gripping jaw l3 and M, respectively, thereon. The handles II and I 2 are pivotally connected together by means of a pin l6, and intersect one that the jaw." are arranged in opposed relationship. It is clear that upon compression of the handles, or bringing of the same together, the jaws I3 and I4 are brought together, while movement of the handles II and I2 away from one another will move the jaws apart. Preferably, the outer surfaces, as well as the edges of the handles II and I2, are knurled to facilitate handling thereof and I also conveniently turn one of the handles, such as the handle I2, upon itself slightly to provide a finger grip II. It is to be understood that the specific type of forceps depicted in the drawings is for purposes of explanation only and that the invention does not reside in a pair of forceps, per se.

The bone-dividing element that I preferably provide in the osteotome of my invention comprises a length of wire I8 that is formed with a knife edge, or sharpened to provide a blade I9 on its outer or exposed end. Any suitable wire.

such as the so-called Bowden wire, can b employed for this purpose. The length of wire I8 is preferably movably housed in a tube 20 which is nearly co-extensive in length with the wire and which serves as a guide therefor. While I have specified and illustrated a Bowden wire having a sharpened outer end as the preferred bone-dividing element, it is to be understood that a blade can be movably mounted in the same manner as the wire with the same efficacious result. In

accordance with the invention, I provide relatively simple means for actuating the bone-dividing element, the actuation thereof effecting the projection and retraction of the wire I8 within predetermined limits so that the blade or knife edge I9 thereof will be injected only the requisite distance into the alveolar process effectively to divide the same without splintering or shattering the plate. To this end, I preferably provide a bellcrank, designated generally by the reference numeral 2|, which conveniently is mounted on one of the handles of the forceps, such as the handle I2, for ready movement by the user when desired. As shown, the inner end of the bone-dividing element I8 is secured to a relatively small link 22 which in turn is pivotally connected, by means of a pin 23, to a link 24 of the bell-crank 2|. The link 24 extends through a slot 26 formed in the handle I2 of the forceps and is pivotally mounted on the axle 21 of the bell-crank which pierces the handle I2 and spans the slot 26 therein.

The mounting arrangement of the bell-crank 2| is such that the manipulating lever 28 thereof, which can be integral with the link 24, is disposed on the outside of the handle I2 for ready access. It will be clear from an inspection of the drawings that pivotal movement of the manipulating lever 28 of the bell-crank in one direction will effect a projection of the blade I9 of the division element I8 into the alveolar process while movement of the manipulating lever 28 in the opposite direction will effect a retraction of the blade from the bone-plate. Preferably, the outer extremity of the division element I8 is slidably mounted or disposed in a recess 0r groove 29 formed in the inner face of the law I4 of the forceps, and the division element is cut to such length that when it is in its fully retracted position, the tip of the blade I9 does not extend beyond the tip of the jaw.

In Figure 2 of the drawings, I have depicted the preferred embodiment of my invention as applied to a tooth 3I to be extracted, this view showing a cross-section of the jaw-bone 32 with e the labial side 33 of the alveolar process at the left and the lingual side 34 of the alveolar process at the right; this view also showing the fibrous lining, or periosteum 36, of the alveolar processes. As indicated, the osteotome of my invention is functionally operable with the jaw that carries the bone-dividing element disposed either on the labial or lingual alveolar process and the two jaws of the forceps are gripping the tooth to be extracted. The full and dotted line showings of Figure 2 of the drawings illustrate the relative positions of the blade I9 of the division element and of the bell-crank 2I upon use thereof for dividing the bony-plate. When the bell-crank has been actuated so as to bring the manipulating lever 28 thereof into engagement with the outer face of the handle I2 of the forceps, the division element I8 will be projected so that the blade I9 thereof is inserted into the alveolar process to fracture (divide) the same, all as indicated by the full line showings of Figure 2. To retract the division element from the plate, the manipulating lever 28 is merely moved in the opposite direction, as indicated by the dotted line showing of Figure 2. It requires but an instant, and one manipulation of the bell-crank to effect the fracture (division) of the bony process, and since the gripping jaws I3 and I4 of the forceps are at the moment engaging opposite sides of the tooth being extracted, the tooth can readily be lifted from the alveolar processes immediately upon the division of the bony plate.

In Figures 3 and 4 of the drawings I have illustrated a modified embodiment of the invention which is generally similar to the preferred embodiment in that it comprises a pair of forceps of somewhat the conventional type including a pair of handles III and H2 having opposed jaws H4 and H3, respectively, extending therefrom; the handles being pivotally connected together in the standard manner by means of a pivot pin II6. In this modification, a bone division element H8 is associated with the forceps and consists of a length of wire, such as a so-called Bowden wire, that is sharpened at its exposed end to form a knife edge or blade II9 thereon; the wire, as in the case of the preferred embodiment being sheathed for protection thereof and for the guiding of the same in a tubing I20. Preferably, the tubing I20 is curved from adjacent the inner side of one handle to the exterior of the other handle in order that the wire I I9 is effectively supported as well as to insure positive sliding movement thereof in the tubing. To this end, a slot H5 is formed in handle III for passing tubing I20 therethrough and I preferably form a recess or groove in the exterior side surface of handle I I2 for snugly and firmly receiving the tubing. Moreover, I preferably cut tube I28 to such a length that it extends slightly beyond the tip of the jaw II3 thus affording a portion thereof for partially separating the gingiva adjacent the tooth to provide for ready access of the blade I I9 of the division element into the underlying bone.

The modification of Figures 3 and 4 is provided with the same means for actuating the division element as in the case of the preferred embodiment, and includes a bell-crank I2I. As shown, the inner end of division element H8 is connected through a small link I22 and a pivot pin I23 to a link I24 which extends through a slot I25 formed in the handle H2 and which is pivotally connected to the axle I2I of the bell-crank I2I. The bell-crank includes a manipulating lever I28 which preferably is formed integral with the link I24 and is mounted exteriorly of the handle H2 for the convenience of the user. In Figure 4 of the drawings, I have depicted the modified embodiment in operable position as applied to a tooth l3| to be extracted, the showing of this View illustrating the jaw bone 132 and the alveolar process with the jaws H3 and H4 gripping opposite sides of the tooth. As so disposed, the osteotome is ready for effecting the division of the bony process and this is effectively accomplished by pressing lever I28 of the bellcrank l2! towards the handle H2 thereby forcing the blade Hi3 into the labial alveolar process to divide the same. The dotted and full line showings of Figure 4 illustrate the positions taken by the manipulating handle in the operation.

Another modification 01 the present invention in an osteotome is illustrated in Figure 5 of the drawings, this modification embodying a different type of a somewhat conventional dental forceps. As shown, the forceps include a pair of pivotally connected handles 2 and H2 having opposed jaws 213 and 2M extending at substantially right angles from the handles adjacent the pivot pin 2H6 joining the handles together. If desired, the free extremity of handle 2!! may be curved slightly, as at 2, for affording a finger grip, and the two handles are preferably knurled to enhance the gripping thereof.

In the modification depicted in Figure 5 of the drawings, I preferably provide a bone division element which is mounted on the forceps p o pin H6 and which consists of an arm 2| 8 having a sharpened extremity to form a knife edge or blade 2!!! thereon; the arm 218 constituting one link of a bell crank that is designated generally by the reference numeral 22!. Bell crank 22! includes a link 224 having an aperture therein for passing the pivot pin H6 and also includes a manipulating lever 228 that is formed integral with the link 226 which in turn is integral with the arm ZIB. As shown, the manipulating lever 228 of the bell crank is extended longitudinally of the forceps alongside the handle 2! l thereof for convenient manipulation by the user. It will be observed from the full and dotted lin showings of Figure 5 that the blade 219 of the link or arm 2H3 can be forced into the alveolar process or buccal-plate adjacent a tooth to be extracted by merely depressing the lever 228, the blade 2|9 being retracted by movement of the lever in the opposite direction.

It is to be understood that "the appended claims are to be accorded a range of equivalents commensurate in scope with the advance made over the prior art.

I claim:

An osteotome comprising a pair of dental forceps including a pair of opposed jaws one of which is formed with a groove in its inner surface, a bone-dividing element slidably supported in said groove, a tube sheathing and guiding said dividing element, and means for sliding said di- Viding element in said tube and said groove for injection into and retraction from a dental alve olar process.

MARSHAL T. SEAGRAVE. 

